Understand Dynamic Range And Change The Way You Photograph

By YPBlending, Tutorials

Photographers who create stunning photographs know 2 things:

They know how to post-process to maximise the potential of their images.

They know how to capture light with their camera.

Now here’s the deal:

Post-processing takes time to master but you can learn to capture light now by understanding what dynamic range is.




What Is Dynamic Range In Photography?

It’s the range of light present in the scene that you’re photographing.

What that means is that light can be very bright, bright, dim or dark. The range of light includes the brightest bright to the darkest dark. Every scene is different and so the range of light or the dynamic range is different.

Cameras Can’t Capture The Full Dynamic Range

Sometimes the digital image sensor in our camera cannot capture the dynamic range of the scene. A scene such as the sunset may have 20 stops of light but our camera can only capture up to about 14 stops!

That’s 6 stops of light not in your image.

That’s exactly the reason you get blown out highlights or shadows that have no details. It is also known as clipping.

This often happens when the very bright and the very dark are present at the same time. Situations like this is called a high contrast scene.

Camera not captured full dynamic range

Our Eyes Can See A Higher Dynamic Range

What we see is often different from what our camera can capture.

Human eyes are complex. When we’re looking at a scene with high contrast, our pupils dilate and constrict very rapidly at the same time to accommodate the light entering our eyes. The nerve cells in the back of the eye can also record a wider range of light compared to a digital image sensor.

dynamic range comparision
Dynamic range as perceived by human eye and image sensor

 

Histogram Is Your Best Friend

I’m sure you know what a histogram is and where to find it in your camera.

The question is:

Have you used it?

Do you know how to read it?

 

 

Use Histogram To Recognize When The Scene Exceeds The Camera’s Dynamic Range

How can you tell when the scene’s dynamic range is higher than what the camera can capture?

Visually?

Yes you can. But it’s not always accurate.

Histogram?

Definitely! A quantitative and binary way to tell you if there’s highlights or shadows clipping. There is no ambiguity about it.

If you haven’t been checking the histogram of your images as you shoot, I would highly recommend you start doing it now!

Reading Histogram Is Easier Than You Thought

I agree with you that interpreting a histogram is not something intuitive and it may take some of us a while to figure out.

I’m going to show you exactly what you need to know to see if you’ve captured the full dynamic range in your image.

reading histogram for dynamic range

A histogram looks like this. You have a graph within a box.

I’ve divided the box into 5 sections. If you’re a Lightroom user, you may already know this.

  1. Blacks – The darkest dark in your image. Any pixels in this section is almost completely black.
  2. Shadows – The brighter dark. You can still see some details in shadows.
  3. Midtones – Most of the pixels should be in midtones, which forms most part of your image.
  4. Highlights – The brighter bright. Similar to shadows, you can see some details.
  5. Whites – The brightest bright. Like the sun because it hurts your eyes if you look directly into it!

 

Also worth mentioning, the vertical line on the far left and the far right. If the histogram touches any of these, some of the pixels are clipped.

 

In Practice

How can you actually use this?

Whenever you’ve taken a photo, check the histogram on the LCD screen of your camera.

If it looks something like this then you’re fine.

histogram for dynamic range

The histogram has touched the far right a little but it’s recoverable, if you’re shooting Raw.

But if it looks something like this:

highlights clipping

The chances are your camera couldn’t capture the whole dynamic range of the scene.

A Stretched Histogram Is A Bad Sign

Did you notice the difference between the 2 histograms above?

The first one has a good distribution in the midtones and a spike in the shadows and the highlights. It’s all within the box.

The second one has been stretched across the box with very thin distribution over the midtones. The majority of the graph are in the blacks and the whites. The far right of the histogram has itself all over the vertical line. That’s highlights clipping.

If you look at the image, you’ll see very bright areas with no details in it.

Clipped Details Are Difficult To Recover

You can always try to use the Highlights and Shadows slider in Lightroom or Adobe Camera Raw to salvage the blown out areas. You may recover some but not all of the details.

Even if you do, any tonal adjustments you apply later will be very restricted because the highlights/shadows can easily be clipped again.

There’s no flexibility in post-processing.

 

The Solution: High Dynamic Range

Yes, there’s a solution to everything!

If your camera can’t capture the full dynamic range of the scene, you can bracket your exposure to create a high dynamic range image, or HDR.

Learn more: How to create HDR images with The Ultimate Guide To Exposure  Blending.




Conclusion

Making full use of the histogram can help you decide if there are shadows or highlights clipping in your image or whether you should bracket images for HDR.

A simple tool that is often underrated by many photographers.

Use it to your advantage today. 🙂

 

Learn More